2,691 research outputs found

    Gordon Valentine Manley and his contribution to the study of climate change: a review of his life and work

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    British climatologist and geographer, Gordon Manley (1902–1980), is perhaps best known for his pioneering work on climate variability in the UK, for establishing the Central England Temperature series and, for his pivotal role in demonstrating the powerful relationship between climate, weather, and culture in post-World War II Britain. Yet Manley made many contributions, both professional and popular, to climate change debates in the twentieth century, where climate change is broadly understood to be changes over a range of temporal and spatial scales rather than anthropogenic warming per se. This review first establishes how Manley's work, including that on snow and ice, was influenced by key figures in debates over climatic amelioration around the North Atlantic between 1920s and 1950s. His research exploring historical climate variability in the UK using documentary sources is then discussed. His perspectives on the relationship between climate changes and cultural history are reviewed, paying particular attention to his interpretation of this relationship as it played out in the UK. Throughout, the review aims to show Manley to be a fieldworker and an empiricist and reveals how he remained committed to rigorous scientific investigation despite changing trends within his academic discipline

    Improving Monolithic Perovskite Silicon Tandem Solar Cells From an Optical Viewpoint

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    Perovskite silicon tandem solar cells are the most promising concept for a future photovoltaic technology. We report on recent progress from an optical viewpoint and disucss how we achieved more than 25 device efficienc

    Thermoelectric Processes and Materials

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    Contains reports on three research projects.United States Navy, Office of Naval Research (Contract Nonr-1841(51)

    Thermoelectric Processes and Materials

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    Contains reports on three research projects.United States Navy, Office of Naval Research (Contract Nonr-1841(51)

    Filaments as Possible Signatures of Magnetic Field Structure in Planetary Nebulae

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    We draw attention to the extreme filamentary structures seen in high-resolution optical images of certain planetary nebulae. We determine the physical properties of the filaments in the nebulae IC 418, NGC 3132, and NGC 6537, and based on their large length-to-width ratios, longitudinal coherence, and morphology, we suggest that they may be signatures of the underlying magnetic field. The fields needed for the coherence of the filaments are probably consistent with those measured in the precursor circumstellar envelopes. The filaments suggest that magnetic fields in planetary nebulae may have a localized and thread-like geometry.Comment: 26 pages with 7 figures. To be published in PASP. For full resolution images see http://physics.nyu.edu/~pjh

    Length scale dependence of dynamical heterogeneity in a colloidal fractal gel

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    We use time-resolved dynamic light scattering to investigate the slow dynamics of a colloidal gel. The final decay of the average intensity autocorrelation function is well described by g_2(q,τ)1exp[(τ/τ_f)p]g\_2(q,\tau)-1 \sim \exp[-(\tau/\tau\_\mathrm{f})^p], with τ_fq1\tau\_\mathrm{f} \sim q^{-1} and pp decreasing from 1.5 to 1 with increasing qq. We show that the dynamics is not due to a continuous ballistic process, as proposed in previous works, but rather to rare, intermittent rearrangements. We quantify the dynamical fluctuations resulting from intermittency by means of the variance χ(τ,q)\chi(\tau,q) of the instantaneous autocorrelation function, the analogous of the dynamical susceptibility χ_4\chi\_4 studied in glass formers. The amplitude of χ\chi is found to grow linearly with qq. We propose a simple --yet general-- model of intermittent dynamics that accounts for the qq dependence of both the average correlation functions and χ\chi.Comment: Revised and improved, to appear in Europhys. Let
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